Before the discovery
of Gliese 581, these planets were the smallest extrasolar planets
yet detected and the first of a new class of rocky terrestrial planets.
The planet orbiting Gliese 876 has a minimum
mass of 5.9 Earths and is 7.5 times Earth’s size. The super-Earth
orbits 2 million miles from its star - or 18 times closer than mercury
orbits our Sun - and completes an orbit every 1.94 days. This super
Earth’s surface temperature is probably between 400 and 750
Fahrenheit (200 and 400 Celsius)
It is intermediate between a true terrestrial
planet like the Earth and a hot version of the ice giants Uranus
This planet is also important in relation
to the alternate formation concept outlined in the later sections
of this website.